[PATCH v2 1/3] mmc: cv1800b: Add sdhci driver support for cv1800b SoC

[Kongyang Liu <seashell11234455@gmail.com>]

Add sdhci driver for cv1800b SoC.

Signed-off-by: Kongyang Liu <seashell11234455@gmail.com>

---

Changes in v2:
- Refactored and simplified some of the code.

 drivers/mmc/Kconfig         |  13 ++++
 drivers/mmc/Makefile        |   1 +
 drivers/mmc/cv1800b_sdhci.c | 116 ++++++++++++++++++++++++++++++++++++
 3 files changed, 130 insertions(+)
 create mode 100644 drivers/mmc/cv1800b_sdhci.c

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index cef05790dd..f7fe6d1042 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -568,6 +568,19 @@ config MMC_SDHCI_CADENCE
 
 	  If unsure, say N.
 
+config MMC_SDHCI_CV1800B
+	bool "SDHCI support for the CV1800B SD/SDIO/eMMC controller"
+	depends on BLK && DM_MMC
+	depends on MMC_SDHCI
+	depends on OF_CONTROL
+	help
+	  This selects the CV1800B SD/SDIO/eMMC driver.
+
+	  If you have a controller with this interface,
+	  say Y here.
+
+	  If unsure, say N.
+
 config MMC_SDHCI_AM654
 	bool "SDHCI Controller on TI's Am654 devices"
 	depends on ARCH_K3
diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
index e9cf1fcc64..3374321e29 100644
--- a/drivers/mmc/Makefile
+++ b/drivers/mmc/Makefile
@@ -60,6 +60,7 @@ obj-$(CONFIG_MMC_SDHCI_ATMEL)		+= atmel_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_BCM2835)		+= bcm2835_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_BCMSTB)		+= bcmstb_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_CADENCE)		+= sdhci-cadence.o
+obj-$(CONFIG_MMC_SDHCI_CV1800B)		+= cv1800b_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_AM654)		+= am654_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_IPROC)		+= iproc_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_KONA)		+= kona_sdhci.o
diff --git a/drivers/mmc/cv1800b_sdhci.c b/drivers/mmc/cv1800b_sdhci.c
new file mode 100644
index 0000000000..2275c53777
--- /dev/null
+++ b/drivers/mmc/cv1800b_sdhci.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2024, Kongyang Liu <seashell11234455@gmail.com>
+ */
+
+#include <dm.h>
+#include <mmc.h>
+#include <sdhci.h>
+#include <linux/delay.h>
+
+#define SDHCI_PHY_TX_RX_DLY  0x240
+#define MMC_MAX_CLOCK        375000000
+#define TUNE_MAX_PHCODE      128
+
+struct cv1800b_sdhci_plat {
+	struct mmc_config cfg;
+	struct mmc mmc;
+};
+
+static void cv1800b_set_tap_delay(struct sdhci_host *host, u16 tap)
+{
+	sdhci_writel(host, tap << 16, SDHCI_PHY_TX_RX_DLY);
+}
+
+static void cv1800b_sdhci_reset(struct sdhci_host *host, u8 mask)
+{
+	sdhci_writeb(host, mask, SDHCI_SOFTWARE_RESET);
+	while (sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask)
+		udelay(10);
+}
+
+static int cv1800b_execute_tuning(struct mmc *mmc, u8 opcode)
+{
+	struct sdhci_host *host = dev_get_priv(mmc->dev);
+
+	u16 tap;
+
+	int current_size = 0;
+	int max_size = 0;
+	int max_window = 0;
+
+	for (tap = 0; tap < TUNE_MAX_PHCODE; tap++) {
+		cv1800b_set_tap_delay(host, tap);
+
+		if (mmc_send_tuning(host->mmc, opcode, NULL)) {
+			current_size = 0;
+		} else {
+			current_size++;
+			if (current_size > max_size) {
+				max_size = current_size;
+				max_window = tap;
+			}
+		}
+	}
+
+	cv1800b_sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
+
+	cv1800b_set_tap_delay(host, max_window - max_size / 2);
+
+	return 0;
+}
+
+const struct sdhci_ops cv1800b_sdhci_sd_ops = {
+	.platform_execute_tuning = cv1800b_execute_tuning,
+};
+
+static int cv1800b_sdhci_bind(struct udevice *dev)
+{
+	struct cv1800b_sdhci_plat *plat = dev_get_plat(dev);
+
+	return sdhci_bind(dev, &plat->mmc, &plat->cfg);
+}
+
+static int cv1800b_sdhci_probe(struct udevice *dev)
+{
+	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+	struct cv1800b_sdhci_plat *plat = dev_get_plat(dev);
+	struct sdhci_host *host = dev_get_priv(dev);
+	int ret;
+
+	host->name = dev->name;
+	host->ioaddr = devfdt_get_addr_ptr(dev);
+
+	upriv->mmc = &plat->mmc;
+	host->mmc = &plat->mmc;
+	host->mmc->priv = host;
+	host->mmc->dev = dev;
+	host->ops = &cv1800b_sdhci_sd_ops;
+	host->max_clk = MMC_MAX_CLOCK;
+
+	ret = mmc_of_parse(dev, &plat->cfg);
+	if (ret)
+		return ret;
+
+	ret = sdhci_setup_cfg(&plat->cfg, host, 0, 200000);
+	if (ret)
+		return ret;
+
+	return sdhci_probe(dev);
+}
+
+static const struct udevice_id cv1800b_sdhci_match[] = {
+	{ .compatible = "sophgo,cv1800b-dwcmshc" },
+	{ }
+};
+
+U_BOOT_DRIVER(cv1800b_sdhci) = {
+	.name = "sdhci-cv1800b",
+	.id = UCLASS_MMC,
+	.of_match = cv1800b_sdhci_match,
+	.bind = cv1800b_sdhci_bind,
+	.probe = cv1800b_sdhci_probe,
+	.priv_auto = sizeof(struct sdhci_host),
+	.plat_auto = sizeof(struct cv1800b_sdhci_plat),
+	.ops = &sdhci_ops,
+};
-- 
2.41.0